Such a sealing device with a tone wheel or a sealing device without a tone wheel has been disclosed in the following: JP-A-2001-65704 (Patent Document 1), JP-A-2003-106464 (Patent Document 2), and (Patent Document 3). The Patent Document 1 discloses a sealing device comprising a first sealing plate and a second sealing plate, one of them being a slinger, which have an L-shaped section and include a cylindrical wall and an upright wall (flange like portion) and a seal lip. The first and the second sealing plates face each other, the tip end of the upright wall of the first sealing plate and the cylindrical wall of the second sealing plate stand face to face with a small radial gap (labyrinth), and the outer side face of the upright wall is set back inwardly from the end face of the cylindrical wall of the second sealing plate.
The Patent Document 2 discloses a sealing device in which the tip ends of the second dust lips (seal lip) elastically and slidably contacting with the inside of a metal ring (slinger) are disposed close so as to face each other, so that the deterioration of shrink range caused by abrasion and settling can be compensated, thereby preventing the ingress of grist and dust into a closed space formed with two dust lips. Further, FIG. 1 of the Patent Document 2 shows an example wherein a part of the second seal portion contacts with the inside of the tip end portion of the outward flange (flange like portion) of the slinger.
The Patent Document 3 discloses an example of a sealing device, in which a permanent-magnetic encoder (tone wheel) is provided to the outer side surface of the ring plate portion of the slinger which constitutes a combined seal ring where the outer side surface of the encoder is covered with a non-magnetic cover plate. The seal ring is provided with an elastic member which has several seal lips all around the inner circumference end of the annular core member which has L-shaped section where the tip end of the seal lip which projects inward in the radial direction contacts with the outer circumference surface of the cylindrical portion which constitutes a slinger, and the tip end of the seal lip which projects to the side in the thrust direction contacts with the inner side surface of the circle ring portion which constitutes a slinger, both tip end of the seal lip contacting with the surface all around the circumference elastically by the elasticity of the seal lips themselves.